<?php
final class Registry {
    private static $data = array();

    public static function get($key) {
        return (isset(self::$data[$key]) ? self::$data[$key] : NULL);
    }

    public static function set($key, $value) {
        self::$data[$key] = $value;
    }

    public static function has($key) {
        return isset(self::$data[$key]);
    }
}
?>